Physics, 06.05.2020 05:37, BlehBlehBlehBleh

G The steam above a freshly made cup of instant coffee is really water vapor droplets condensing after evaporating from the hot coffee. What is the final temperature (in °C) of 240 g of hot coffee initially at 80.0°C if 2.50 g evaporates from it? The coffee is in a Styrofoam cup, and so other methods of heat transfer can be neglected. Assume that coffee has the same physical properties as water.

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answered: jdenty3398

the final temperature = 74.33°C

Explanation:

Using the expression Q = mcΔT for the heat transfer and the change in temperature .

Here ;

Q = heat transfer

m = mass of substance

c = specific heat

ΔT = the change in temperature

The heat Q required to change the phase of a sample mass m is:

Q = m L_v

where;

L_v is the latent heat of vaporization.

From the question ;

Let M represent the mass of the coffee that remains after evaporation is:

ΔT = $\frac{mL_v}{MC}$

where;

m = 2.50 g

M = (240 - 2.50) g = 237.5 g

L_v = 539 kcal/kg

c = 1.00kcal/kg. °C

ΔT = $\frac{2.50*539 \ kcal /kg}{237.5 g *1.00 \ kcal/kg . ^0C}$

ΔT = 5.67°C

The final temperature of the coffee is:

T_f = T_i - ΔT

where ;

T_I = initial temperature = 80 °C

T_f = (80 - 5.67)°C

T_f = 74.33°C

Thus; the final temperature = 74.33°C

answered: Guest

Acetic acid /əˈsiːtɪk/, systematically named ethanoic acid /ˌɛθəˈnoʊɪk/, is a colourless liquid organic compound with the chemical formula ch3cooh (also written as ch3co2h or c2h4o2). when undiluted, it is sometimes called glacial acetic acid. vinegar is no less than 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. acetic acid has a distinctive sour taste and pungent smell. in addition to household vinegar, it is mainly produced as a precursor to polyvinyl acetate and cellulose acetate. it is classified as a weak acid since it only partially dissociates in solution, but concentrated acetic acid is corrosive and can attack the skin.acetic acidnamespreferred iupac nameacetic acidsystematic iupac nameethanoic acidother namesvinegar (when dilute); hydrogen acetate; methanecarboxylic acid[1][2]identifierscas number64-19-7 3d model (jsmol)interactive image3dmetb00009 reference506007chebichebi: 15366 chemblchembl539 chemspider171 drugbankdb03166 echa infocard100.000.528ec number200-580-7e numbere260 (preservatives)gmelin reference1380iuphar/bps1058keggd00010 meshacetic+acidpubchem cid176rtecs numberaf1225000uniiq40q9n063p un number2789inchiinchi=1s/c2h4o2/c1-2(3)4/h1h3,(h,3,4) key: qtbsbxvteameqo-uhfffaoysa-n smilescc(o)=o

answered: Guest

it is called kinetic energy

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G The steam above a freshly made cup of instant coffee is really water vapor droplets condensing aft...